Portable electronic devices (e.g., mobile phones, personal data assistants, laptops, etc.) are widely used today for communication and computing applications. Conventional portable electronic devices typically include generally flat exterior surfaces to reduce development and production cost. However, a user may have difficulty stably holding such an electronic device in a desirable position because the flat exterior surfaces typically cannot adequately accommodate contours of the user's fingers. The flat exterior surfaces can also reduce the mechanical strength of the electronic device because flat surfaces can readily transmit, instead of dispersing, applied forces. These limitations can reduce the user's satisfaction with operating the electronic device.